Field of the Invention
The present invention relates to surface treated medical devices namely staples, dental floss and sutures and methods of forming the same.
Background Information
Medical Device Surface Treatment Background
Devices used in the medical field must be manufactured using materials, such as biomaterials, having particular surface properties so that the device functions without causing adverse effects to the patient.
Biomaterials are typically made of inert metals, polymers, or ceramics to ensure durability and to ensure that the materials do not adversely react with the physiological environment with which they come into contact, such as with blood or tissues. More particularly, many biomedical devices may or may not require blood compatible, infection resistant, and/or tissue compatible surfaces. For example, it is often desirable to manufacture medical devices, such as catheters, that have properties that discourage adherence of blood or tissue elements to the device.
It is also desirable for certain biomaterials, such as those for implants, to be anchored stably into the tissue environment into which they are implanted. For example, it may be desirable for specific implants, such as certain types of catheters and stents, to be non-inflammatory and anchored to the surrounding tissues. Moreover, it may be desirable for certain biomaterials to prevent bacterial growth during a course of a procedure, or as a permanent implant so as to prevent infection of a patient in contact with the biomaterial. Initial contact of such materials with blood may result in deposition of plasma proteins, such as albumin, fibrinogen, immunoglobulin, coagulation factors, and complement components. The adsorption of fibrinogen onto the surface of the material causes platelet adhesion, activation, and aggregation. Other cell adhesive proteins, such as fibronectin, vitronectin, and von Willebrand factor (vWF) also promote platelet adhesion.
In addition, disposable surgical tools may become infected with bacteria during a course of a long operation and reuse of the tool during the operation may promote bacterial infection in the patient. For certain tools used in particular applications, it may be desirable therefore to prevent any bacterial growth on the surfaces of these tools during the course of an operation.
Additionally for permanently implanted materials it would be desirable to prevent bacterial growth that would lead to a biomaterial or device centered infection. In the latter the only remedy is eventual removal of the implant.
Adverse reactions between materials and blood components are predominant factors limiting the use of synthetic materials that come into contact with physiological fluids.
A number of approaches have been suggested to improve the biocompatibility and blood compatibility of medical devices. One approach has been to modify the surface of the material to prevent undesirable protein adhesion by providing the material with a low polarity surface, a negatively charged surface, or a surface coated with biological materials, such as enzymes, endothelial cells, and proteins. Another approach has been to bind anticoagulants to the surface of biologically inert materials to impart antithrombogenic characteristics to the materials. Still another approach used in the art has been the copolymerization of various phospholipids which are used as coating materials for various substrates. Partial polymeric backbone coatings have also been used in a similar fashion. However, many of these methods can result in a leaching or “stripping off” of the coating.
In devices requiring the transfer of gases, for example, in blood oxygenators requiring the exchange of oxygen and carbon dioxide through a membrane or porous fiber, there are additional drawbacks. Often surfaces that have been rendered biocompatible by the coating of biomolecules attract phospholipids. Phospholipids that adhere to the surface coat the pores and wet the surface of the device, making it hydrophilic. Water adversely affects gas transfer, making the oxygenator significantly less effective.
There is a need in the art to develop processes for preparing substrates coated biomolecules that demonstrate biocompatibility and blood compatibility, while maintaining gas permeability.
Hernia Background
Hernias have plagued humans throughout recorded history, and descriptions of hernia reduction date back to Hammurabi of Babylon and early Egyptian writings. A hernia is usually a protrusion or sac formed by the lining of the abdominal cavity, the peritoneum. The hernia sac protrudes through the hernia defect, i.e. a hole or weak area, in the fascia. The fascia is the strong layer of the abdominal wall that surrounds the muscle. There are various types of hernias including ventral hernias, incisional hernias, inguinal hernias, hiatal hernias, femoral hernias, diaphragmatic hernias, diverticular hernias, barth hernias, epigastric hernias, interstitial hernias, sciatic hernias and umbilical hernias, defined largely by the location of the hernia defect. This is merely an illustrative and not a comprehensive listing of hernia classifications.
Surgery is essentially the only treatment that can permanently fix a hernia. Original hernia surgery utilized the patients existing tissue to repair the defect and this technique is now known as “pure tissue” repair of a hernia defect. Dr. Bassini has been noted as an early pioneer in successful pure tissue repair of hernias when in 1888 he reported a reduction in the recurrence rate of pure tissue hernia repair to about 10% (from a conservative estimated 30-40% rate earlier) with his procedure that combined an understanding of anatomy with an application of surgical thinking and surgical technique. This 10% recurrence rate is quite impressive when noted that it was achieved at a period without antibiotics, primitive anesthesia and at a time when patients often suffered with their hernia until they reached a giant size before submitting to surgery. For well over a century, Bassini's pure tissue repair procedures, with several modifications (e.g. Halsted, McVay, Tanner, and Shouldice) have helped preserve useful life in hundreds of thousands cases.
Hernia repair prosthetics have been developed, also called hernia repair patches, hernia repair fabrics and hernia repair meshes, for use in what is known as a tension free repair of a hernia defect. The hernia prosthetic generally plugs and/or bridges the gap forming the defect and the patient's tissue is not “stretched” over the defect, thus allowing the tissue to remain “tension free”. The tension-free repair is invariably linked to Dr. Lichtenstein whose work and progress over two decades culminated in what is known as the tension free Lichtenstein repair. The precise amount of reoccurrence varies with the type of hernia and the associated procedure utilized, but in essentially all cases the “tension free” prosthetic repair substantially reduces reoccurrence of hernias over the pure tissue repair, a minimized recovery period. Further, tension free prosthetic hernia repair further yielded a decrease in post operative patient pain and thus has become the most popular repair for hernia defects.
Numerous surgically implantable hernia repair prosthetics have been proposed. Hernia repair mesh prosthesis formed of synthetic materials such as polypropylene (PP), polyester (PET), and polytetrafluoroethylene (PTFE), and combinations thereof are some of the most common. Within the meaning of this patent application the term mesh references a flexible fabric formed by a netting of filaments with mesh openings between the filaments forming an open texture. These synthetic prosthetics are generally intended for permanent placement within a patient's body space. Hernia repair mesh prosthesis formed of non-synthetic or biological materials have also been proposed, with some biological prostheses designed for permanent placement within a patient's body space and others designed for partial or complete absorption into the patient's body over time (hopefully after the hernia defect has been fully repaired).
In certain procedures, including incisional and umbilical hernia repair and chest reconstruction, the synthetic hernia repair prosthetic may come into direct contact with the sensitive abdominal viscera. Postoperative adhesions between the prosthesis and the intestine may occur, potentially leading to intestinal fistulization. Various approaches to reducing the incidence of postoperative adhesions arising from the use of prosthetic materials have been proposed by the prior art. It has further been suggested to cover the prosthesis with peritoneum or other tissue, where available or adequate to close the defect, to form a natural biological barrier between the implant and the bowel.
Also proposed has been the placement of a physical barrier between the surgical site and the surrounding tissue where adhesions are most commonly encountered. For example In an article entitled “Heparin Releasing Anti-adhesive Membranes” by Y. Noishiki and T. Miyata published in Jinko Zoki, 14(2), p. 788-79 1 (1985), a collagen membrane (special treated human amnion) having protamine cross-linked into the collagen network was immersed in 1% heparin solution so the heparin was ionically bound to the protamine which had been cross-linked in the collagen. The resultant heparinized collagen membrane was stitched into place covering a wound on the serosal membrane of the large intestines of dogs. The animals were examined after 3 days, 60 days, 173 days and 687 days. No signs of adhesions were found. These collagen membranes were not biodegradable, since much of these membranes remained even after 687 days. The heparin was released slowly and steadily, so that 76% of the heparin originally present in the membrane was released over a period of three months.
Jenkins et al., “A Comparison of Prosthetic Materials Used to Repair Abdominal Wall Defects”, Surgery, Vol. 94, No. 2, August 1983, pg. 392-398, describes a technique of placing an absorbable gelatin film (GELFILM® brand) freely between a piece of MARLEX® brand knitted polypropylene monofilament mesh and the abdominal viscera. The gelatin film dissolved after one week. Thereafter, the incidence of adhesions was reported to be the same as with using the Marlex mesh alone.
U.S. Pat. No. 4,840,626 discloses a process of preventing post-surgical adhesions which comprises positioning as a physical barrier between the site of the surgical activity and neighboring tissue with a distinct physical barrier formed as a heparin-containing matrix of an oxidized regenerated cellulose adhesion-preventative barrier fabric. This patent also discloses the process of administering heparin topically to an internal body organ during surgery for the purpose of preventing surgical adhesions which comprises applying an oxidized regenerated cellulose fabric containing heparin absorbed on it to the outer surface of an internal body organ, with the fabric (or other matrix) being drapable, conformable, adherent to body organs, and substantially absorbable within thirty (30) days in the body.
U.S. Pat. No. 5,002,551 discloses a physical barrier formed of a knitted oxidized regenerated cellulose (referenced as “Intercede (TC7)”). The patent indicates that other physical barriers include silicone elastomers and absorbable gelatin films. Clinical studies of Intercede (TC7) were reported in “Prevention of Postsurgical Adhesions by Intercede (TC7), An Absorbable Adhesion Barrier: A Prospective, Randomized Multicenter Clinical Study”, Fertility and Sterility, Vol. 51, No. 6, June 1989, pg. 93-938. Such physical barriers alone are not sufficient to reinforce the abdominal wall or to repair abdominal wall defects.
U.S. Pat. No. 5,077,372 discloses a medical device coated with an antithrombogenic agent, covalently linked to the amino groups of the polyurethane coating. These coating reactions and heparinizations are carried out directly on the device's surface. Such methods as disclosed herein, however, have been suggested to suffer from decreased bio-activity, and consequently, increased thrombogenicity.
U.S. Pat. No. 5,593,441 is a representative example of one synthetic polymeric hernia mesh prosthesis and discloses ventral hernia and/or chest wall reconstruction prosthesis that is a polypropylene mesh covered with an adhesion resistant barrier, such as a sheet of expanded PTFE. In the repair of ventral hernias and in chest wall reconstruction, the composite prosthesis is positioned with the barrier relative to the region of potential adhesion, such as the abdominal viscera. Similarly, International Publication No. WO 97/35533 proposed a composite prosthesis in which one side of a layer of mesh material is completely covered with a layer of barrier material. The mesh material promotes biological tissue in-growth while the barrier material retards biological tissue adherence thereto. PTFE, however, has yielded increased complications relating to treatment of postoperative infections.
U.S. Pat. No. 5,795,584 describes a post-surgical anti-adhesion device further described as surgical adhesion barriers and methods of using such surgical adhesion barriers are provided. Surgical adhesion barriers according to the patent have at least one layer of a bioabsorbable material comprising copolymers and/or block copolymers derived from trimethylene carbonate. Alternatively, a multilayer surgical structure having one or more bioabsorbable layers superimposed on a non-absorbable layer is useful for minimizing or preventing formation of fibrous adhesions between a healing trauma site and adjacent surrounding tissue. Alternatively, a bioabsorbable nonwoven fabric in adherent contact with at least one bioabsorbable layer of foam, film, mesh, web or woven fabric is also provided. One or more medicinal agents may be interposed between or disposed within any of the aforementioned layers.
U.S. Pat. Nos. 6,497,650 and 7,154,804 also disclose prosthesis for repairing a tissue or muscle wall defect. The prosthesis comprises a layer of repair fabric having first and second and an edge that extends between the first and second surfaces. The prosthesis also includes a barrier that is inhibits the formation of adhesions with adjacent tissues and organs. The barrier may overlap a portion of the first and second surfaces. The barrier may be formed separate from and attached to the layer of repair fabric to permanently cover a portion of the edge. The repair fabric may be formed from a material which is susceptible to the formation of adhesions with sensitive tissue and organs. The cord protector may be formed from material which inhibits the formation of adhesions with sensitive tissue and organs. The barrier may overlie a portion of at least one of the first and second surfaces of the repair fabric.
U.S. Pat. No. 6,723,709 discloses biomaterials essentially constituted by esterified derivatives of hyaluronic acid or by cross-linked derivatives of hyaluronic acid for use in the surgical sector, particularly for use in the prevention of post-surgical adhesion.
U.S. Pat. No. 6,969,400 discloses a synthetic implant with nonimmunogenicity coating described as crosslinked polymer compositions that include a first synthetic polymer containing multiple nucleophilic groups covalently bound to a second synthetic polymer containing multiple electrophilic groups. The first synthetic polymer is preferably a synthetic polypeptide or a polyethylene glycol that has been modified to contain multiple nucleophilic groups, such as primary amino (—NH.sub.2) or thiol (—SH) groups. The second synthetic polymer may be a hydrophilic or hydrophobic synthetic polymer, which contains or has been derivatized to contain, two or more electrophilic groups, such as succinimidyl groups. The compositions may further include other components, such as naturally occurring polysaccharides or proteins (such as glycosaminoglycans or collagen) and/or biologically active agents. Also disclosed are methods for using the crosslinked polymer compositions to affect adhesion between a first surface and a second surface; to effect tissue augmentation; to prevent the formation of surgical adhesions; and to coat a surface of a synthetic implant.
U.S. Pat. No. 7,172,765 notes that other materials have also been used to form physical barriers in an attempt to prevent adhesions, including silicone elastomers, gelatin films and knit fabrics of oxidized regenerated cellulose (hereinafter ORC). In some cases This patent notes that it is suggested that heparin, heparinoid, or hexuronyl hexosaminogly can be incorporated into the matrix of an ORC fabric or other matrices of hyaluronic acid, cross-linked and uncross-linked collagen webs, synthetic resorbable polymers, gelatin films, absorbable gel films, oxidized cellulose fabrics and films which are fabricated into a form that is said to be drapable, conformable and adherent to body organs and substantially absorbable within 30 days. This patent references U.S. Pat. No. 4,840,626, EPA Publication No. 0 262 890 and EPA Publication No. 0 372 969 as examples of this point. However, this patent suggests it is difficult to precisely control the degradation rate of many of these materials and scar tissue can result from use of many of the materials.
U.S. Pat. No. 7,749,204 discloses a reinforced absorbable multilayered fabric for use in tissue repair and regeneration described as directed to a method of using a multilayered fabric comprising a first absorbable nonwoven fabric and a second absorbable woven or knitted fabric in tissue repair and regeneration. The patent adds that additionally, the reinforced absorbable multilayered fabric may contain bioactive agents to aid in the repair or regeneration of tissue. Examples of bioactive agents include cell attachment mediators, such as peptide-containing variations of the “RGD” integrin binding sequence known to affect cellular attachment, biologically active ligands, and substances that enhance or exclude particular varieties of cellular or tissue ingrowth.
U.S. Pat. No. 7,815,923 discloses an implantable graft material that is suitable for implantation within a patient including isolated tissue material remodeled in a body cavity. The patent states “In addition to being cross linked, the ECM material can be treated (e.g., brought into contact, impregnated, coated, etc.) with one or more desirable compositions, such as anticoagulants (e.g., heparin), growth factors, other desirable property modifiers, and the like to modify the tissue properties.”
U.S. Pat. No. 7,883,694 discloses a method for preventing the formation of adhesions following surgery or injury which is described as providing “crosslinked polymer compositions that include a first synthetic polymer containing multiple nucleophilic groups covalently bound to a second synthetic polymer containing multiple electrophilic groups. The first synthetic polymer is preferably a synthetic polypeptide or a polyethylene glycol that has been modified to contain multiple nucleophilic groups, such as primary amino (—NH.sub.2) or thiol (—SH) groups. The second synthetic polymer may be a hydrophilic or hydrophobic synthetic polymer, which contains or has been derivatized to contain, two or more electrophilic groups, such as succinimidyl groups. The compositions may further include other components, such as naturally occurring polysaccharides or proteins (such as glycosaminoglycans or collagen) and/or biologically active agents. Also disclosed are methods for using the crosslinked polymer compositions to effect adhesion between a first surface and a second surface; to effect tissue augmentation; to prevent the formation of surgical adhesions; and to coat a surface of a synthetic implant.”
Related to surface coatings in general, U.S. Pat. No. 7,919,137 is directed to particularly to implantable or insertable medical devices which contain adherent polymeric layers and discloses medical “devices having adherent polymeric layers with depth-dependent properties” disclosing “a method of forming a medical device is provided, which includes: (a) contacting a substrate with a solution that contains (i) one or more types of polymers, (ii) a solvent that contains one or more types of solvent species, and (iii) one or more optional agents, for example, one or more therapeutic agents, among others; and (b) removing the solvent from the solution, thereby forming a polymeric layer on the substrate. The composition of the solution is changed over the course of forming the polymeric layer. In another aspect of the invention, a medical device is provided, which includes a substrate and a polymeric layer over the substrate. The polymeric layer contains a copolymer that contains differing first and second monomers. The lower surface of the polymeric layer contacting the substrate has a surface concentration of the first monomer relative to the second monomer that is higher than that of the upper surface of the polymeric layer opposite the substrate.” The patent states that “Examples of medical devices benefiting from the present invention include implantable or insertable medical devices, for example, catheters (e.g., urological or vascular catheters such as balloon catheters and various central venous catheters), guide wires, balloons, filters (e.g., vena cava filters and mesh filters for distil protection devices), stents (including coronary vascular stents, peripheral vascular stents, cerebral, urethral, ureteral, biliary, tracheal, gastrointestinal and esophageal stents), stent coverings, stent grafts, vascular grafts, abdominal aortic aneurysm (AAA) devices (e.g., AAA stents, AAA grafts), vascular access ports, dialysis ports, embolization devices including cerebral aneurysm filler coils (including Guglilmi detachable coils and metal coils), embolic agents, hermetic sealants, septal defect closure devices, myocardial plugs, patches, pacemakers, lead coatings including coatings for pacemaker leads, defibrillation leads, and coils, ventricular assist devices including left ventricular assist hearts and pumps, total artificial hearts, shunts, valves including heart valves and vascular valves, anastomosis clips and rings, cochlear implants, tissue bulking devices, and tissue engineering scaffolds for cartilage, bone, skin and other in vivo tissue regeneration, sutures, suture anchors, tissue staples and ligating clips at surgical sites, cannulae, metal wire ligatures, urethral slings, hernia meshes, artificial ligaments, orthopedic prosthesis such as bone grafts, bone plates, joint prostheses, orthopedic fixation devices such as interference screws in the ankle, knee, and hand areas, tacks for ligament attachment and meniscal repair, rods and pins for fracture fixation, screws and plates for craniomaxillofacial repair, dental implants, or other device that is implanted or inserted into the body.” Similar disclosures are in related U.S. Pat. Nos. 7,914,807, 7,914,806, 7,901,726, 7,897,171, and 7,767,726.
U.S. Pat. No. 7,935,773 is directed to a device designed to close tissue openings and discloses “Water-swellable copolymers and articles and coatings made therefrom” in which describes that “compositions in accordance with this disclosure are water-swellable and can thus be used to close openings in tissue. The compositions include a copolymer containing repeating units of two or more monomers selected from the group consisting of 3-sulfopropyl acrylate potassium salt (“KSPA”), sodium acrylate (“NaA”), N-(tris(hydroxyl methyl)methyl)acrylamide (“tris acryl”), and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS). The compositions can formed into a desired shape or may be used to coat at least a portion of a medical device, such as a hernia mesh, suture or surgical staple. After being dried, the copolymer will swell upon contact with moisture, such as blood or other bodily fluid.” The reference also teaches that, optionally, therapeutically beneficial compounds may be incorporated into the present compositions, and, after application or implantation of the article or coated device, released there from.
These U.S. patents are incorporated herein by reference in their entirety. Not all of the above disclosures are directed to hernia prosthesis but do give technical background for general medical device construction and techniques to control tissue adhesion. Some of these earlier hernia repair prosthetics are complex. Although these medical advances in the field of hernia repair prosthetics are acknowledged for their usefulness and success in reducing the incidence of reoccurrence of the hernia, there remains a need for greater improvements in properly managing post operative adhesions in synthetic hernia mesh prosthesis and providing a solution that is cost effective to manufacture and implement.
Suture and Staple Background
Dermal wounds, whether from accidental injury, invasive medical procedures or cosmetic surgical modifications often result in some degree of scar formation. Scars can lead to adverse cosmoses, loss of functionality and can have significant adverse effects on a patient's quality of life. As such, wound healing and scar formation are highly researched areas and there is great potential to apply more recent findings toward innovative improvements to deliverable technologies. Thus a leading concern for all procedures in the wound care/elective surgery industry is a perfect cosmetic outcome with lack of visible scarring. Or substantial minimization of such scarring. Surgical practices have evolved considerably to minimize or hide scars from elective surgical procedures and various topical treatments have come to market which aim to reduce existing scars. Still, few products aim to actively inhibit scar formation at the extracellular level in the earliest stages of wound healing.
Fundamentally, scaring is the result of the body's rapid response to a wound, and a natural part of the healing process. Fibroblasts accumulate and proliferate in the wound site and hurriedly generate extracellular collagen matrix to strengthen the wound and allow for migration of cells.
In the suture, and to a lesser extent the surgical staple, fields the “coating” of these substrates with a variety of bioactive molecules is known, although most processes fail to immobilize the bioactive molecule and none of the prior art proposals appear to be demonstrably effective at promoting wound healing for minimizing scars, which almost none of these techniques have found commercial implementation.
U.S. Pat. No. 8,012,173 notes that so “far, only one polyglycolide-based thread material, marketed by Ethicon, which is coated with the antiseptic triclosan has been available on the market. This antiseptic is a chlorinated biphenyl derivative which has an antiseptic effect on gram-positive bacteria.” The '173 patent itself teaches a surgical suture material with an antimicrobial surface with the surface exhibiting a coating containing a) at least one fatty acid, b) octenidine dichloride and/or dequalinium chloride and c) optionally oligomeric lactic acid esters. In addition, a process for coating surgical suture material is described which is characterized by the fact that the thread material is wetted with a homogeneous methanolic solution of octenidine dichloride and/or dequalinium chloride and subsequently the methanol is evaporated, a coating forming on the thread surface.
U.S. Pat. No. 7,837,708 discloses a suture which is combined intraoperatively with autogenous blood components. At least one strand of suture is placed into a sterile container and blood obtained from a patient is separated, using a centrifuge, for example, to retrieve certain healing components such as autogenous growth factors, to obtain an autogenous blood suspension. The autogenous blood suspension is added to the sterile container containing the strand of suture. The suture wicks up biologic components of the autogenous blood suspension to produce an enhanced suture. Surgical repairs using the enhanced suture are conducted by suturing a tear to itself or to bone, for example. Post-operatively, the biologic components leach from the suture to accelerate healing of the repair. Note also U.S. Pat. No. 2,493,943 essentially teaches catgut impregnated with human blood and U.S. Pat. No. 2,615,450 teaches the formation of hemoglobin containing sutures.
U.S. Patent Application Publication Number 2006-0286289 teaches an Intra-operative coating of sutures with therapeutic proteins, particularly growth factors such as rhGDF-5. including contacting a suture to a device containing a therapeutic agent.
U.S. Pat. No. 6,689,153 discloses a coated/impregnated anchoring device and/or suture to prevent infection, deliver site specific drugs, and deliver human growth factors to the surgical site. The coatings can include anti-microbial agents to prevent or fight infection en route to and at the surgical site. The coatings can also include site specific drugs and/or human growth factors to fight infection, anesthetize tissue and/or bone en route and at the site, promote tissue regeneration, promote bone regeneration, and/or other desired medical processes.
U.S. Pat. No. 6,878,757 discloses compositions with antimicrobial properties contain a fatty acid ester salt mixed with a bioabsorbable copolymer. These compositions are useful in forming coatings for surgical articles, including multifilament sutures. See also U.S. Pat. No. 7,829,133.
U.S. Pat. No. 5,716,376 discloses suture coatings made of a mixture of fatty acid esters, including calcium stearoyl lactylate, with a copolymer containing caprolactone. The coatings taught by this patent are used for absorbable sutures and other surgical articles and, in the case of sutures, impart improved properties to the suture, such as knot security, surgeon's throw, lubricity, knot run down, and/or knot repositioning.
It is known that suture materials are often coated with various substances to improve their handling characteristics. For example, U.S. Pat. Nos. 5,147,383, 5,123,912, 5,102,420, 5,100,433, 5,089,013, 4,844,067, 4,080,969, 4,043,344, 4,047,533, and 4,027,676 disclose coated surgical sutures with improved knot tie down properties.
U.S. Pat. No. 5,032,638 discloses a suture coating comprising a copolymer of poly (Beta-hydroxybutyrate) and a stearoyl lactylate containing alkaline-earth metals, and notes that calcium stearoyl lactylate and magnesium stearoyl lactylate can be added as lubricants.
U.S. Pat. No. 4,705,820 discloses a suture coating comprising a “random copolymer” and a lubricant, which can be a stearoyl lactylate.
U.S. Pat. No. 5,939,191 discloses a gut suture coated with a bioabsorbable copolymer obtained by polymerizing a major amount of epsilon-caprolactone and a minor amount of at least one other copolymerizable monomer in the presence of polyhydric alcohol as initiator.
U.S. Pat. No. 4,649,920 discloses a suture coated with an absorbable composition consisting essentially of a high molecular weight poly(alkylene oxide).
U.S. Pat. No. 3,896,814 discloses a collagen or catgut thread treated fatty compounds or derivatives of fatty compounds, such as glycerine, polyoxyalkylenes such as polyethylene glycol, or glycol derivatives.
These U.S. patents and U.S. Patent Application Publications are incorporated herein by reference in their entirety. The concept of providing a bioactive molecule on a suture or staple is well known and the above patents establish the amount of research in this effort and the lack of commercialization of such proposals evidence that such proposals have, to date, been ineffective at solving the stated problems in a cost effective manner. There remains a need in the art to provide a suture or staple with bioactive molecules to promote healing in a cost effective efficient manner.